The present embodiments relate to mitral valve detection. The mitral valve (MV), located between the left atrium (LA) and the left ventricle (LV), controls the unidirectional blood flow from the LA towards the LV. The MV is a complex cardiac structure including two leaflets, the mitral annulus and tendineae chordae. The leaflets are attached to the left heart through the fibrous mitral annulus, whereas the other extremity, called the free-edge, is tethered to the papillary muscles through the tendineae chordae. During diastole, the leaflets open as the blood enters the LV. When the myocardium starts to contract, the leaflets close to prevent the blood from going back to the atrium.
Mitral valve disease is one of the most common heart valve diseases, with a prevalence increasing with age. MV regurgitation or mitral insufficiency is the most common form of valvular heart diseases. MV regurgitation is characterized by reverse blood flow from the LV to the LA and high pressure gradients across the mitral valve during systole. In severe cases, a surgical intervention may be necessary to repair, or even replace the incompetent valve. Suturing the two mitral leaflets together at the regurgitant hole may help patients with severe mitral insufficiency due to leaflet prolapse or calcified annulus. In the percutaneous edge-to-edge technique, the leaflets are attached using a clip (e.g., MitraClip) delivered through a catheter.
Transthoracic echocardiography (TTE) is an imaging modality used for early detection and assessment of mitral regurgitation (MR). Ultrasound images, such as three-dimensional (3D) transthoracic images, may be used to evaluate MV function in patients. Color flow imaging on the TTE, for example, may reveal a jet of blood flowing from the LV into the LA during ventricular systole. With real-time full volume echocardiography, transthoracic B-Mode volumes are acquired along with 3D color flow imaging (CFI) for every heartbeat. A combination of measurements, based on both morphological and functional observations, is used to assess disease progression and make therapy decisions. However, the complexity of MV anatomy and its fast dynamics make accurate quantification of the MV anatomy from medical images difficult.
Automatic or semi-automatic methods have been proposed to make MV assessment more efficient. The shape and motion of the annulus or the mitral leaflets is modeled from transesophageal echocardiography (TEE) or computed tomography (CT) images. However, TEE is invasive and CT uses x-rays. These modeling approaches have not been designed to cope with images with considerable lower quality, such as TTE even though TTE imaging may be more simply performed.